Over recent years, the market for wireless communications has enjoyed tremendous growth. Wireless technology now reaches or is capable of reaching virtually every location on the earth. With tremendous success of wireless telephony and messaging services, it is hardly surprising that wireless communication is beginning to be applied to the realm of personal and business computing. No longer bound by the harnesses of wired networks, people will be able to access and share information on a global scale nearly anywhere they venture.
The major motivation and benefit from evolving WLANs is increased mobility. Network users can move about almost without restriction and access LANs from nearly everywhere. In addition to increased mobility, WLANs offer increased flexibility. Meetings can be arranged, in which employees use small computers and wireless links to share and discuss future design plans and products. Such “ad hoc” networks can be brought up and torn down in a very short time as needed, either around the conference table and/or around the world. WLANs offer the connectivity and the convenience of wired LANs without the need for expensive wiring or re-wiring.
However, even with the fastest laptop, productivity while traveling can fall because of poor access to the Internet or company intranet. Despite the revolution of the Global System for Mobile communication (GSM), laptop users need faster access to download large files and to synchronize their e-mails quickly. The emerging mobile information society demands that data is available whenever and wherever. As a solution to this problem an operator WLAN (OWLAN) solution has been proposed which brings broadband access to the laptop or terminal device in specific places like airports, convention centers, hotels and meeting rooms. Thus, mobile network operators are able to offer broadband access to the internet, corporate intranets or other service machineries from virtually anywhere in the world. Thus, a public WLAN service with own WLAN roaming feature can be provided.
In packet-switched cellular networks, such as the GPRS or UMTS network, the users service descriptions are specified by Access Point Names (APN). GPRS is a common packet domain core network used for both GSM and UMTS networks. This common core network provides packet-switched services and is designed to support several quality of service levels in order to allow efficient transfer of non real-time traffic and real-time traffic. A Serving GPRS Support Node (SGSN) is provided to keep track of the individual location of a mobile terminal and performs security functions and access control. Additionally, a Gateway GPRS Support Node (GGSN) provides interworking with external packet-switched networks, and is connected with SGSNs via an IP-based packet domain backbone network. In the backbone network, the APN is in practice a reference to the GGSN to be used. In addition, the APN may, in the GGSN, identify the external network and optionally a service to be offered. Further details concerning the use and structure of APNs are defined e.g. in the 3GPP specification TS 23.003.
In GPRS a user can access home network services located behind access points identified by their APNs. When a user connects to a GPRS service, i.e. establishes a Packet Data Protocol (PDP) context as specified e.g. in the 3GPP specifications TS 23.060, the APN information selected by the terminal device or user equipment (UE) or the user of the terminal device is sent from the terminal device to the network in a PDP context establishment signaling. This information consists of APN and optionally username and password if required to access the service behind the selected APN. In the GPRS network, this information is used to select suitable GGSN. The information also arrives to the selected GGSN and the GGSN uses this information further to establish a connection to a network node behind the GGSN, e.g. a corporate intranet or an operator service node. If provided, the username and password are delivered to the concerned network node behind the GGSN to allow authorization of the connection.
However, in the proposed public or operator WLAN systems, an operation similar to the GPRS PDP context activation is not provided. In particular, there is no dedicated signaling for setting up services between a WLAN terminal device, i.e. WLAN UE, and the WLAN network or network behind the WLAN network. Such services can be e.g. access to the user's corporate intranet, third party ISP style services, mobile operator services, So far, users have only been able to connect to the Internet directly via the local WLAN access network. Therefore, GPRS type of service selection and activation is not possible via the WLAN network, which thus forms a drawback in the proposed public or operator WLANs.